This invention is related to the interconnection component that is the passive devices and/or the active devices that the interconnection component that composes an electric circuit is connected between the electrode parts electrically.
These days, the motherboard printed circuit board for system LSI application and other applications, are mounted on the LSI bear chips, MCMs (multi-chip module), semiconductor packages, discrete passive components such as the capacitor, the resistor with higher system integration, higher density mounting and interconnecting technologies.
Number of discrete components, especially passive devices, on a motherboard has been increasing by the demand of highly function of the electric products. For example, in a cellular phone, 300–500 passive components are mounted with respect to one IC chip; in a personal computer, about 2,200 passive components are mounted with respect to one microprocessor. A space for the surface of the printed circuit board for components mounting is limited, thus there is limitation for using surface mount technology to mounting a large number of components on the printed circuit board. Moreover, it becomes difficult to secure interconnection reliability that the tendency of mounting components are increasing brings to increasing the number of interconnection sections.
Since the rates of the passive components that occupied the mounting area of the printed circuit board assembly are increasing, the embedded passive and/or active devices technology has been developed. The components embedded printed circuit boards are using inner layer lamination sheet that made by conventional subtractive method and/or buildup method, etc. For example, a capacitor is formed in the printed circuit board by the steps of: forming a dielectric layer between a power layer and a ground layer; and forming electrodes by etching. Further, a resistor is formed in the printed circuit board by the steps of: forming a high resistivity metal layer between the power layer and the ground layer; and forming electrodes by etching. By adopting the embedded components printed circuit board can reduce the number of passive components from the surface of printed circuit board without sacrifice the components mounting density. Furthermore, the thin film capacitor can be located nearest section of semiconductor devices for reducing signal wiring length. As the results, the electrical characteristic of the embedded components printed circuit board can be improved.
However, there is the circuit design limitation for the typical embedded components printed circuit board by subtractive method and/or buildup method, due to the inner layer material or passive element forming material. Because embedded capacitors and resistors are formed with particular inner layers, such as between power layer and ground layer, then materials are laminated for complete printed circuit board. In addition, there is the fabrication limitation that capacitors and resistors cannot be provided in the same layer of the printed circuit board due to the same kind of elements can be provided in one layer. Therefore, new means for flexibility designing circuits and reducing number of interconnecting sections without expanding an occupying space of electric components is required now.
A conventional means for electrically interconnecting a semiconductor chip to a printed circuit board is shown in FIG. 4. Interconnecting sections or terminals 53 of the semiconductor chip (or a semiconductor package) 51 and the printed circuit board 52 are solder balls or metal bumps. The semiconductor chip 51 is electrically interconnected to land sections 54 of the printed circuit board 52, and further electrically interconnected to power line (layer) 56 and ground line (layer) 57 by plated through-hole sections 55. The terminals 53 are made of a good conductive material with low resistance so as to secure interconnection reliability and electrical performance.